The invention relates to a guiding device for agitators, in particular submersible motor agitators. Submersible motor agitators are normally mounted in large pools, for example sewage treatment pools, with guiding devices being arranged at the pool edge. Guiding devices such as this in this case have to carry out the following tasks:
First, the submersible motor agitator must be guided from the pool edge into the pool. Furthermore, a stop must be provided on the guiding device, which defines the position of the unit in the pool and ensures the necessary distance between the agitating member and the pool bottom. Furthermore, the guiding device is intended to provide the capability to vary the outlet flow direction, which is induced by the submersible motor agitator, with reference to the pool wall. Furthermore, the guiding device must withstand all the forces which occur during operation of the submersible motor agitator and must introduce the forces and moments into the pool wall or the pool top and the pool bottom. In this case, it is necessary to compensate for the weight forces of the submersible motor agitator itself, the torque about the submersible motor agitator axis, the axial thrust through the agitating member, any lateral forces caused by the flow in the pool and by any aeration devices, as well as forces caused by inhomogeneity or density differences of the liquid medium.
Furthermore, the guiding device must be designed such that any inclinations of the pool bottom can be taken into account, with wall mounting being possible.
In known guiding devices, a submersible motor agitator is guided from the pool edge into the pool via quadrilateral tubes with a square cross section. A portion of the guiding devices has a rigidly attached guide tube. In this case, it is not possible to vary the outlet flow direction of the flow induced by the submersible motor agitator.
In general, it is desirable in the case of submersible motor agitators for the size of the housing units for the submersible motor agitator itself and the components of the guiding device to be kept as small as possible, in order to keep transport costs and transport volumes as low and small as possible. In this case, it may be advantageous for the guiding device to make use of components which do not necessarily need to be delivered at the same time but can easily be procured additionally by the customer in the delivery location.
In addition, guiding devices are already known which include the capability to adjust the outlet flow direction of the flow induced by the submersible motor agitator. Two fundamental designs are in principle known in this case. On the one hand, there is a design in which the guide tube axis also forms the rotation axis at the same time. In another design, the rotation axis is located outside the guide tube.
An increased manufacturing effort is required for guiding devices which have a rotation axis outside the guide tube axis. In this case, a shorter quadrilateral tube is welded onto the lower face of the guide tube, that is to say in the area of the pool bottom, and can be mounted on a guide pin on the pool bottom. In some alternative embodiments, an additional welded part is pushed into the lower face of the guide tube and then forms the rotation point outside the guide tube axis. This results in more stringent requirements for the connection of the two parts, in order to allow the forces which are exerted on the system to be safely absorbed. Other guiding devices are known in which a holder for a spherical element is welded on the lower face of the guide tube and is mounted in a bush on the pool bottom, and thus forms a rotation point outside the guide tube axis.
On the other hand, in solutions in which the rotation axis lies within the guide tube, the attachment and removal of the submersible motor agitator during lowering into the pool and/or removal from the pool are particularly disadvantageous. In known embodiments, the submersible motor agitator can only be lifted out when the submersible motor agitator axis is at right angles to the pool wall. Furthermore, the adjusting lug by means of which the outlet flow direction is adjusted must be completely removed in order to allow the submersible motor agitator to be detached from the guide tube.
U.S. Pat. No. 4,581,182 discloses a guiding device which has a lower support for the guide tube so as to allow matching to the inclination of the pool bottom. This mount has no capability to rotate about the guide tube axis, as a result of which the outlet flow direction of the agitator flow induced by the agitator cannot be adjusted. Furthermore, in order to remove the submersible motor agitator, the guides for the sliding carriage on the side of the guide tube facing the wall must be removed.
In contrast, in U.S. Pat. No. 4,671,872, it is possible to vary the outlet flow direction of the submersible motor agitator using the guiding device. An upper attachment of the guide tube is provided with four clamping jaws, in a circular clamp, for this purpose. This arrangement is also subject to the disadvantage that it is complex and difficult to remove the guides for the sliding carriage on the side of the guide tube facing the wall.
A guiding device according to U.S. Pat. No. 4,431,597 is constructed in a similar manner. In this case, the capability of the guide tube to rotate is arranged considerably above the pool upper edge. However, the disadvantage in this case is that the entire sliding carriage must be removed when the submersible motor agitator is to be detached.